Propeller cuff assembly



y 1959 w. BLANCHARD, JR 2,893,496

u PROPELLER CUFF ASSEMBLY Original Filed March 1:5, 1952 v 2 Sheets-Sheet 1 INVENTOR.

BY NAZI/96f BIA/161M190 J/l.

y 1959 w. BLANCHARD, JR 2,893,496

PROPELLER CUFF ASSEMBLY Original Filed March 13, 1952 2 Sheets-Sheet 2 I N V EN TOR.

mum! Bum/4B0 #3.

MM, lddueaw M! w H15 ATM/MHZ? United States Patent 2,893,496 PRoPELLER CUFF ASSEMBLY Wallace Blanchard, Jr Dayton, Ohio, assignor to Gen- The presentinvention.iel'ates a) spinnersrer rapener's and more particularly to spinners for variable pitch propellers of the contra-rotationtype. i v e l I This is a divisional application of copendingf'parent application Serial No. 276,312, filed March 13,- 1952, now abandoned. V A One of my objects is y to provide a spinner assembly for acontra-rotatio n aircraft propeller wherein the shank portions of the propeller blades and the hubs are enclosed to preserve the streamliningof the aircraft.

The aforementioned and other objects are accomplishedin the present invention by providing a spinner shell of substantially generated conic form. The Spinner shell includes a front or nose portion, which is secured to and rotates with an outboard propeller element, and an oppositely rotating rear; portion, which is secured to an inboard propeller element. Eaeh spinner portion is providedwith; a' plurality of apertures or cutouts, disposed substantially 120 apart, through which blades .of the propeller elements protrude. U I H Each propeller blade has attached thereto aroundits shank portion, a cuff element which perfects the airfoil contour of the blade portion projecting through the spi n ner cutout. The c-uflf elements are movable with the blades during pitch changing movements thereof. The outer edges of the cuffs mergeinto the blade surfaces, and they inner edges of the cuifs terminate proximate the surface of the spinnershell. The nose portion of the spinner shell is provided with a radially inward and outward extending well adjacent each cutout, and the rear-portion of the spinner shell is provided with a radially inward extending well adjacent each cutout. Disposed in each well and mounted for rotation therein is a cylindrical bulkheadrnember which is anchoredv to the propellerblade. The cylindrical bulkhead member is attached to the cutfelement-and is provided with a resilient sealing member that engages the inner surface of the wellto prevent air leakage at the cutouts. Additional means are provided on each cuff element in, contiguous relation with the trailing edge of the blade for drawing the. leading edge thereof against the leading edge of the blade.

Further objects and advantages of the present invention will be apparent from the following description; reference'being had to the accompanying drawings wherein a preferred'embodiment of the present invention is clearly shown, and wherein similar reference characters'denote similar parts throughout the several views.

In the drawings:

Fig. l is an elevatiohal view of a propeller provided with the spinner of the present invention.

Fig; 2 is an. enlarged longitudinal'view takenalong lines. 2.-2 of Fig. 1, partly in sectionand partly in elevation with some of the blades removed.

Fig;- 3 isan enlarged fragmentary view of an outboard propeller blade and the'nose portion of thespinner taken generally along lines 3-3.'of Fig.v 1, partly in section and partly in elevation.

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2 Fig. 4 is a sectional view taken amngimes" 4-4 of Fig. 3.

Referring particularlyto Fig. lot the drawings, a spinner 'shell 1 is shown having a plurality of cutouts 2-, 4, 6, in a nose portion 8 ofthe. spinner shell. A rearportion 9 of the spinner shell is" likewise provided with threecutouts, two of which, 3 and 5,- are shown in Fig. 2. The cutouts in each spinner portion are substantially 120 apart, and the nose and. rear spinner portions rotate in opposite directions. I As is shown more clearly in Fig. 2 the nose portion 8. of the spinner shell is anchoredto an outboard propeller element 10 by means of bulkheads 12 and 14. The rear portion 9 of the spinner shell is likewise anchored-to an inboard propeller element 11 by means of bulkheads 13 and 15. The outboard propeller element 10 is provided'with three blades 16, 18 and 20, which are rotatably mounted in a hub 22 for movement about their longitudinal axes. Attached to the outboard hub 22 is an outboard regulator 24,- which automatically controls the pitch changing movements. of the outboard propellerelement blades ina manner disclosed in the Martin et al. patent 2,421,514. The inboard propeller element 11 is likewise provided with three blades, only one,- 1 7, ofwhich is shown: ,The'blades ofthe inboard propeller element. arelikewise rotatably mounted for movement about their longitudinal, axes in a propeller hub 19, which has rigidly attached thereto a regulator 21. The inboard and outboard propeller elements rotate in opposite directions, and, hence; the spinner portions associated therewith rotate in opposite directions.

The configuration of theentire spinner shell compris- 1 ingfront and rear portions is substantially a generated cone. The spinner portions are designed to blend in with a nacelle of the aircraft and provide proper fairing for the hubs so that streamlining of. the aircraft is aflorde'd. Referring to Figs. 2 and 3, the nosepoi'tion 8 of the spinner will'be described in detail. The cutouts in the nose portion 8 are substantially circular. As the assemblies associated with each cutoutof the nose portion 8 are identical, a detailed description of the assembly associated with cutout 2 is deemed to be sufficient. Extending radially outward and inward of the cutout 2 is a truncated cylindrical'rn'ember 26. A major portion of the circumference of the member 26 extends raidally outward of the nose portion 8, and the minor portion of the circumference of member 26 extends radially inward of the nose portion 8 within the cutout 2. The major portion of the inner circumferential edge of the member 26 is flange connected at 28 to the spinner shell 8, and the minor portion of the outer circumferential edge of member 26 is flange connected at 30 to the spinner shell.

The blade 16 of the outboard propellrelemm projects through the cutout 2. The blade -16 is provided with a shank portion 32, which merges with an airfoil portion at one end and a root end portion 34at the other end. The root end portion 34 of the blade is mounted for rotation in the hub 22. A cuff ring 36 is formed as an integral part of theblade on the shank portion 32 thereof. Secured to the cuff ring 36 by means of screw devices 38 is a cylindrical member 40; At-

' tached to the outer end of member 40 by means of rivets or the like, 42, is a bulkhead assembly 44 having a cylindrical extension 46, This structure forms a seal assembly preventing air leakage at the cutouts. Secured to the end of cylindrical extension 46 is a resilient seal. 48 of substantially V-shaped configuration. One leg of the V is secured by any suitable means to cylindrical extension 46, and the other leg of the seal 48 extends radially outward and engages the inner surface of the well 26. Thus, bulkhead cooperates with the well 26 by means of the seal 48, and prevents air leakage at the cutout. The bulkhead member 44 is attached by means of screw devices or rivets 50 to a cuff element 52 as sociated with the blade 16.] Cuff elements 52 surround theshank portions of the blades 16, 18 and 20 and perfect the airfoil 'contour of the shank portions of these blades. v

The cuff elements 52 comprise a member 54 of generally airfoil configuration. The inner edge of member 54 is closed by means of an extension of the bulkhead 44, which is secured thereto. In this manner the cuff elements 52 are retained by the bulkhead 44 and cannot move outwardly under the urge of centrifugal force when the propeller is rotating. The outer edge of the member 54 merges with the leading edge of the blade 16 and also merges with the thrust and camber surfaces thereof. The member 54 is of one-piece construction, and the two ends thereof are secured together by means of a bracket 56, which is secured to the inner surfaces of member 54 by means of rivets or the like.

The bracket 56 also supports means for drawing the leading edgemember 54 against the leading edge of the blade 16. These means comprise a bolt 58 journaled in the bracket 56. The'outer end of the bolt 58 is provided with a slot 60 into which a tool may be inserted for rotating the bolt 58. The bolt 58 threadedly engages a nut 62 which is anchored to the bracket 56. The other end of the bolt 58 has attached thereto a grooved resilient member 64, of elastomeric, rubber-like material as shown in Figs. 3 and 4. The grooved resilient member 64 is disposed in contiguous relation to the trailing edge of the blade and the legs thereof, which define the groove 66,'engage the camber and thrust surfaces adjacent the trailing edge of the blade. It is apparent that upon rotation of the bolt 58 in one direction, resilient member 64 will be urged away from the nut 62. By reason of the nut 62 being rigidly anchored to the bracket 56, which, in turn, is rigidly anchored to member 54, movement of resilient member 64 away from nut 62 will draw the leading edge of member 54 into engagement with the leading edge of the blade 16, as is shown at 68. The clamping means likewise draws the cuff edges into engagement with the thrust and camber surfaces of the blade. In this manner the cuffelements are removably attached to the blades of the inboard and outboard propeller elements.

After the leading edge of the member 54 has been drawn into engagement with the leading edge of the blade 16, a cover member 70, comprising substantiallya U- shaped member having oneend closed at 72, is attached to the bracket 56 by screws or other suitable means. The cover member 70 completes the airfoil section of the cuff element 52, and is provided with an edge disposed in contiguous relation with the trailing edge of the blade. The cover member 70 also provides protection for the bolt 58 and its associated parts.

The rear portion 9 of the spinner shell is similar to the construction of the nose portion 8. That is, it is likewise provided with outouts but, as is shown in Fig. 2, the cutouts of the rear portion 9 are provided with radially inward extending wells. Extending radially inward of the spinner shell and within the cutout 3 is a truncated cylindrical member 23, which is flange connected at 25 to the spinner shell. A bulkhead member 27 having a cylindrical extension 29 islikewise secured to a member 31, which is anchored to a cuff ring 33 on the shank portion of the blade 17. The inner edge of cylindrical extension 29 is likewise provided with a seal member 35, which cooperates with the inner wall of member 23 to prevent air leakage at the cutout 3. The other end of the bulkhead member 27 is attached to a cuff element 37, which is of exactly the same'construction as the cuff elements 52. Hence, a detailed description of cuff elements 37 is not deemed to be necessary. The inner edges of the cuff elements 37 and 52 terminate proxi- 4 mate the peripheral surface of the spinner shell portions 8 and 9.

It is apparent from the foregoing description that the spinner construction of the present invention will streamline the shank portions of the propeller blades and will enclose the hubs of the propeller elements. Moreover, by reason of the sealing means disposed in each well, air leakage at the cut outs is prevented during pitch changing movements of the blades. Moreover, by reason of the cuff clamping means, it is a very simple operation to remove and replace the cutf elements, should the occasion arise.

While the embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted.

What is claimed is as follows:

1. In combination with an aircraft propeller blade having an airfoil portion and a shank portion around which a cuff is attached, means perfecting the airfoil contour of a part of said shank portion, said means comprising a cuff element having clamping means for maintaining the merging edges of said cuff element and the surfaces of said blade in engagement, said clamping means comprising a nut anchored to a bracket attached to said cutf element, a bolt threadedly engaged with said nut and a grooved resilient member attached to said bolt for engaging the trailing edge of, said blade, and a cover member secured to said cuff bracket for perfecting the airfoil contour of said cuff.

2. In combination with a propeller blade having a shank portion merging with an airfoil portion at one end and a root end portion at the other end, a cuff ring formed as an integral part of the blade adjacent the shank portion thereof, a cylindrical member secured to said cuff ring, a bulkhead assembly having a cylindrical extension attached to one end of said cylindrical member, a calf element retained by said bulkhead assembly, a bracket attached to inner surfacearea of said cuff element, a nut anchored to said bracket, a bolt reciprocally threaded into said nut, a grooved reciprocable member attached to one end of said bolt capable of being moved by said bolt and nut into contiguous relation with the trailing edge of the blade, said bolt and grooved member being capable of drawing said cuff element into engagement with the leading edge and sides of the blade, said cuff element being held by said bulkhead assembly with said cylindrical member secured to the cuff ring to prevent movement thereof outwardly under the urge of centrifugal force during propeller rotation, and a cover attachable to said bracket for protecting said bolt and completing the airfoil section of said cuff element.

3. In combination with an aircraft propeller blade having a shank portion merging with an airfoil portion including thrust and camber surfaces at one end and a root end portion at the other end, means perfecting airfoil contour of a part of said shank portion, said means comprising a cuff element having an outer edge merging only with the leading edge of the blade as well as thrust and camber surfaces thereof, said element being of onepiece construction having two ends with inner surfaces adjacent thrust and camber surfaces of said blade, a bracket attachedacro ss the two ends at the inner surfaces of said cuff element, a clamping means reciprocable relative to' said bracket and engaging the trailing edge of the blade, said clamping means including a nut anchored to said bracket attached to said cuff element, a bolt threadedly engaging said nut, means associated with said bolt engaging the trailing edge of the blade, said clamping means drawing the outer edge of said cuff element into engagement with the leading edge and thrust and camber surfaces of the blade, and a U-shaped cover member secured to said cuff bracket and having an edge in contiguous relation with the trailing edge of said blade for completing the airfoil contour with said cuff element.

Fimlbillation with an aircraft propeller blade having an airfoil portion and a shank portion, means perfecting the airfoil contour of a part of said shank portion, said means comprising a cult element having a bracket carrying clamping means for engaging a trailing edge of said blade and for drawing a leading edge of said culi element against a leading edge of the blade, said clamping means including a nut anchored to said bracket attached to said eufi element, a bolt threadedly engaging said nut, and a grooved resilient member of elastomeric material carried by said bolt and adapted for resiliently engaging the trailing edge of said blade.

5. In combination with an aincraft propeller blade having an airfoil portion and a shank portion around which a end is carried, means perfecting the airfoil contour of a part of said shank portion, said means oom- 15 2,289,400

References Cited in the file of this patent UNITED STATES PATENTS Laddon Aug. 16, 1938 Woods July 14, 1942 

